Caviar is the undisputable jewel of the luxury food scene, conjuring up images of expensive hors d’oeuvres served at the finest social functions. But how did these tiny black edible pearls become so prized? The fine delicacy consists of fish eggs, also called roe, harvested from the sturgeon. There are 27 different species of sturgeon, giving us different types, textures, colours and flavours of caviar— although ironically, the flesh of the sturgeon itself is not particularly prized. The most expensive and desirable caviar comes from the Beluga,...